SELF DOUBT

Question

Hi Can any one explain by Diagram. It will be more Easy to understand

Thanks,

Let R represents an one to many relationship between entities E1 and E2 and the set A, B attributes represent the key of R (A is key for E1 and B is key for E2) then which of the following statements is correct

1.   The FD, A→B will only holds
2.  The FD, B→A will only holds
3.  (a) and (b) hold together
4.   Neither (a) nor (b) holds

Answer 1

may be 2 is the answer. if the relation A has three values (1,2,3) and relation B has three values (1,2,3). since relationship is one to many , we can form relationship instances (1,1),(1,2),(2,3). now b attribute can identify attribute A.

Comments

FD means?

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Functional dependencies

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@Mayank Yes I think B is the correct answer.